The present invention relates to electrical connectors and more particularly to modular jacks used in residential telephone systems.
Telephone companies (or “telcos”) typically maintain telephone wiring up to a demarcation point where the telco feed interfaces with the house or premises wiring. The demarcation point is located in a network interface device (NID). The NID has two “sides”—one for the phone company and one for subscriber access. At least the telco-side of the NID terminates in a modular jack. To connect the inside wiring to the telco feed, a jumper cable terminated with a modular plug is plugged into the modular jack. The other end of the jumper is either hardwired to the subscriber-side or is plugged into a modular jack connect to the subscriber-side. This arrangement allows the telco feed and the inside wiring to be isolated for troubleshooting and maintenance.
Competition for local telephone service subscribers is growing. Broadband service providers offer digital telephone service, which turns voice calls into digital packets for dispatch over an IP network. A cable company can now offer cable TV, telephone service and broadband connections on one bill to its subscribers.
When a cable subscriber elects to convert from telco-provided local phone service to cable-provided local service, the inside wiring is connected through a cable voice interface device to the cable provider's network. Typically, a cable modem is connected to a media terminal adapter (MTA) that is connected to the inside wiring through a wall jack. To isolate the cable equipment from the telco feed, the telco feed is disconnected from the inside wiring at the demarcation point. Where a NID has been provided, this requires removal of the jumper connecting the telco side of the NID to the subscriber-side of the NID be removed.
The modular plug/modular jack arrangement makes this a simple task. However, the risk to the cable operator and to the telco is that at some point in the future, the subscriber or a service technician may reconnect jumper using at now-empty modular jack. Cable voice interface devices may be then be exposed to potentially damaging signals from the telco feed. Similarly, signals from the MTA may risk damage to telco equipment at the central office. One solution to this problem is to remove the inside wiring from the NID and provide a new cross connect from the inside wiring to the cable voice interface. However, this adds labor and equipment cost to the installation of the cable voice service.
What is needed is an inexpensive means for preventing the reconnection of inside wiring to a telco feed at a NID in a cable voice installation.